Elephant d'afrique

Scientific name: Loxodonta africana

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Taxonomy

Scientific name:

Loxodonta africana

Threat level:

Near threatened

Authority:

Blumenbach, 1797

Common names:

Elefante africano (English)
African elephant (English)
Éléphant africain (French)

Assessment Information

Version:

3.1

Year assessed:

2008

Assessor(s):

Blanc, J.

Evaluator(s):

Balfour, D., Craig, C., Dublin, H.T. & Thouless, C. (African Elephant Red List Authority)

Justification:

Background Considerations and Choice of Criteria
The species is the largest terrestrial animal and has been the subject of considerable research, but continent-wide distribution and density estimates are difficult to obtain for any one time period. To a large extent this is due to the enormous range covered by the species (and thus the cost of estimating its numbers) as well as to the wide variety of habitats it occupies (often woodland and forest where visibility is poor from the ground as well as from the air; see Habitats list). These difficulties, coupled with the differential influence that various historical factors have played in different parts of the continent, result in a continental picture of the status of the African Elephant that varies considerably – qualitatively and quantitatively – across its range.

Although our knowledge of the status of African Elephants across their range has been progressively improving since the mid-1990s, when considerable resources began to be channelled into compiling and producing regular updates of the continental status of elephants with a standardized measure of certainty (Said et al. 1995; Barnes et al. 1999; Blanc et al. 2003; Blanc et al. 2007), large gaps still remain.

In investigating the Red List Criteria (Version 3.1) against these realities, it became clear to the group of assessors that the variability in population trends and levels of uncertainty would preclude a full quantitative Red List assessment, such as would be conducted under criterion E. It was therefore agreed that a compromise approximation would have to be made, and that the African Elephant Specialist Group would be best placed to undertake this task. In order to facilitate the process, extensive use was made of the Guidelines for Application of IUCN Red List Criteria at Regional Level (IUCN 2003).

The criterion used for the categorization was criterion A. Criteria B, C and D are not applicable as the species currently occupies more that 20,000 km² and there are more than 10,000 mature individuals. No quantitative analysis was conducted and therefore criterion E does not apply.

Subcriterion A2a was used because some of the major causes for decline, such as habitat loss due to human population expansion, have not ceased and may not be reversible. While the data used in the assessment are based on direct observation, the population size reduction over three generations is only inferred (see below).

A generation time of 25 years, calculated as the average age of reproductive females, was established using data from many culling exercises in Kruger National Park, South Africa (I. Whyte, unpubl.).

There are no credible estimates for a continental population prior to the late 1970s (i.e. about one generation ago). In addition, African elephant population trends in the course of the 20th century are believed to have differed considerably across the different African sub-regions (see Figure 1 in the attached PDF). In Eastern Africa, for instance, there is a general consensus that there was a peak (regional population maximum) around the late 1960s and early 1970s, followed by a decline in the 1980s and subsequent recovery in recent years (Blanc et al. 2005; 2007). In Southern Africa, which now harbours the largest known populations on the continent, elephant numbers are believed to have been at their lowest around the turn of the 20th century, and to have been increasing steadily ever since. The magnitude of the decline in Eastern Africa has in all likelihood been offset by the magnitude of the increase in Southern Africa. In West Africa, major declines probably occurred well before the turn of the 20th century and the population has remained at low levels ever since. There is insufficient information on sub-regional trends in Central Africa prior to 1977, but elephant populations are believed to have declined since. This is important as Central Africa accounts for a large proportion of the estimated continental range, but our knowledge of its current population size is the weakest.

Thus for the continental (global) population, an extrapolation back to the beginning of three generations (1932) would be plagued with high levels of uncertainty. Clearly, forward extrapolation to 2057 would also be troubled by uncertainty, not only for the reasons cited above, but also because of the variety of causes for decline and the nature of the current and likely future threats - mainly habitat loss and illegal hunting for both meat and ivory - which are in themselves variable in intensity across the continent.

Taking these problems into account, the consensus among contributors to this assessment was that it would be an appropriate and acceptable compromise, more likely to err on the conservative side, to assume the continental population of three generations ago to be equal to that of one generation ago.

Methodology and choice of data
Current population data were obtained from the African Elephant Status Report 2007 (Blanc et al. 2007; hereafter referred to as AESR 2007).

Approximately one elephant-generation (25 years) ago, a comprehensive attempt at a continental estimate was presented in the African Elephant Action Plan (Douglas-Hamilton 1979; hereafter referred to as AEAP 1979). This document and the references cited therein have been used extensively to determine the status of the species one generation ago, and to provide the basis for comparison with AESR 2007 estimates for this Red List assessment.

In order to make the figures from the two time periods as comparable as possible, it is important to understand the nature of the different data types presented in the AEAP 1979 (Douglas-Hamilton 1979) and the AESR 2007 (Blanc et al. 2007).

Estimates in the AESR 2007 are broken down into four mutually exclusive categories of certainty – namely Definite, Probable, Possible and Speculative – using transparent and objectively defined rules, as described in Blanc et al. (2007). These rules are such that an estimate can be split into one or more of the above categories. It is important to note, however, that all figures in the AESR 2007 were determined by some form of actual ground-based estimate of the area concerned – be it a systematic count or a guess. No extrapolations into unassessed range are included in the AESR 2007.

The AEAP 1979 presents two kinds of data, namely estimates and extrapolations. Estimates were pooled from a wide range of first-hand sources which used a wide variety of methods - ranging from standardized, systematic population surveys to plain guesswork.

No attempt was made in the AEAP 1979 to classify estimates in terms of quality or reliability, but for the purposes of this assessment, and based on the estimation methodologies, these data are taken as comparable to the cumulative speculative estimates (i.e. the sum of Definite, Probable, Possible and Speculative figures) found in the AESR 2007.

The extrapolations included in the AEAP 1979 provided elephant population estimates for all areas of assumed elephant range not covered by estimates. Such extrapolations were arrived at by multiplying assumed elephant densities by the assumed areas of elephant ranges. The AEAP 1979 thus includes a category of estimate not included in the AESR 2007. For the purposes of this assessment, the additional extrapolations presented in the AEAP 1979 are not used in the comparisons between the two time periods.

In both the AEAP 1979 and the AESR 2007 the estimates used for comparison cover approximately 50% of estimated elephant range, with the rest of range remaining effectively unassessed.

In addition, there are three important points to note on how figures were used:

1. Use of alternative sources. In a number of cases, to estimate numbers in the late 1970s, alternative sources were used instead of the estimates provided in the AEAP 1979. This was done in a systematic fashion, always following the guideline that where an alternative estimate was available, it was only used if it was higher than that reported in the AEAP 1979, even if the alternative estimate was dated as more recent than 1979. This was viewed as more conservative, as it was widely agreed in the assessing group that the number of African Elephants has probably declined in the past 25 years.

2. Removal of underestimated national figures. In cases where a national estimate in the AEAP 1979 was lower than those in the AESR 2007 and there were no alternative sources, the country was completely removed from the analysis. This was the case for two countries, namely Gabon and Liberia.

3. Data for Sudan. Elephant population surveys were conducted in a number of areas of South Sudan after the publication of the AESR 2007. The estimate used for South Sudan in this assessment was taken from the recent surveys (Elkan and Grossmann pers. comm.) and not from the AESR 2007.

Changes to status
The African Elephant is listed as Near Threatened on the basis of an inferred decline of 25% between 1979 and 2007, as this falls short of the 30% threshold required for a Vulnerable listing under criterion A2a. The current assessment therefore represents a downlisting of the species with respect to its previous listing as Vulnerable (VU A2a) in the 2004 IUCN Red List. It is believed that the change in status reflects recent and ongoing population increases in major populations in Southern and Eastern Africa. These increases are of sufficient magnitude to outweigh any decreases that may be taking place elsewhere.

Regional assessments
The status of African Elephants varies considerably across the species' range. These differences broadly follow regional boundaries, and are partly a result of the different historical trends, as outlined above. To better reflect this variation in status, it was decided to include in this assessment regional-level listings for the four African regions in which elephants occur (see Table 1 in the attached PDF). The methodology and criteria used in these regional assessments is identical to that used for the global assessment, but employing only the relevant subsets of data.